The Best Steel Mesh Sizes For Concrete

If you’ve ever poured concrete, you know the feeling. You smooth it out, it looks perfect, and you walk away proud. Then you come back the next morning to find a crack running right down the middle. It’s heartbreaking. Concrete gets weak under pressure and it needs backup.

That backup is steel mesh, a flat grid of wire that sits inside the slab like a hidden suit of armor. But don’t think all mesh is the same. The size of the openings is everything. If you pick the wrong gauge or spacing, that mesh is just expensive trash, and your slab is doomed.

Here are important things you need to know about picking the right steel mesh size.

The standard size for patios and floors:

If you are pouring a floor for a shed or a patio in the backyard, you want the standard sheet. This is the mesh that most hardware stores keep in stock. It usually has squares that are six inches by six inches. The wire itself is thick enough to hold the concrete tight.

This size works because the concrete is not holding up a building. It is just holding up people walking or a table and chairs. The wide squares give the concrete enough grip to stop cracks from spreading wide.

Smaller mesh for thin slabs:

Sometimes you want to pour concrete that is thin. Maybe you are making a garden path or a small step. If the concrete is only four inches thick, you cannot use the big six inch mesh. The steel needs to sit in the middle of the concrete.

If the mesh is too big for a thin slab, it ends up sitting on the ground instead of inside the concrete. That does no good at all. For thin work, you want a tighter mesh. Look for squares that are four inches by four inches.

Heavy mesh for driveways:

Cars are heavy. Trucks are even heavier. When you pour a driveway, the weight pushes down hard on the concrete. Over time, that weight can make the slab bend. You need a mesh that can handle that bending. For driveways, you want the heavier stuff.

The squares might still be six inches, but the wire itself is thicker. Sometimes you will see mesh with rectangles instead of perfect squares. The long way runs one direction, and the short way runs the other.